Aesthetic, self-aligning shingle for hip, ridge, or rake portion of a roof

ABSTRACT

There is provided a hip, ridge, or rake shingle, which includes a shingle panel and at least one rigid back member. The shingle panel has a substantially planar lower surface. The at least one rigid back member has a length substantially the same as or greater than the length of the shingle panel. The rigid back member is attached to the substantially planar lower surface of the shingle panel. The rigid back member includes a step in thickness in a cross-sectional plane perpendicular to the substantially planar lower surface and parallel to the longitudinal axis of the rigid back member. In addition, the thickness of the rigid back member at the high level of the step is greater than the thickness of the rigid back member at one of its ends. There is also provided an asphaltic adhesive including from about 62% to about 99% by weight of an asphalt cement; from about 0.5% to about 15% by weight of a first thermoplastic having a glass-transition temperature in the range from about 190° F. to about 260° F.; and from about 0.5% to about 15% by weight of a second thermoplastic having a glass-transition temperature in the range from about −55° F. to about 0° F.

BACKGROUND

[0001] The present invention relates generally to the construction of ashingle for covering the hip, ridge, or rake portion of a roof. Inparticular, the present invention relates to the construction of a hip,ridge, or rake shingle having a thick, aesthetic appearance and aself-aligning mechanism for the rapid and uniform installation of anumber of such shingles.

[0002] In the roofing art, it is well-known to attempt to enhance theappearance of a non-wood hip, ridge, or rake shingle by increasing theheight of such a shingle to simulate the height of a wood shingle.Examples of such shingles are provided in U.S. Pat. Nos. 5,471,801;5,377,459; 5,247,771; and 3,913,294. In addition, another example ofsuch a shingle is provided by the Z-Ridge® shingle product sold by ElkCorporation of Ennis, Tex. These shingles are constructed using creativefolding designs for the shingle web material to create an overallshingle appearance that is thicker than that of the web material alone.

[0003] While these shingles provide an improved appearance over unfoldedor flat shingles, they all suffer from common deficiencies. First, allof the shingles are difficult to align while installing and, thus,require great care in installation to avoid unsightly irregularappearances. Second, when installed, the shingles produce an exaggerated“saw-tooth” appearance, which is different than the more levelappearance of wood shingles. Third, the shingles are difficult (if notimpossible, in some cases) to install over “ridge vent” products (to bediscussed below). Moreover, even in the best case, installation is atwo-step process: the “ridge vent” products are nailed in place,followed by the installation of the ridge shingles. Finally, with timeand heat, the folds in the shingles tend to compress and the shinglestend to droop and lose their wood-like appearance.

[0004] It is an object of the present invention to provide a hip, ridge,or rake shingle that overcomes these deficiencies.

SUMMARY OF THE INVENTION

[0005] According to the present invention, there is provided a hip,ridge, or rake shingle, which includes a shingle panel and at least onerigid back member. The shingle panel has a substantially planar lowersurface and an upper surface. The back member has a length that issubstantially the same as or greater than the length of the shinglepanel. The back member is attached to the substantially planar lowersurface of the shingle panel. The back member includes a step inthickness in a cross-sectional plane perpendicular to the substantiallyplanar lower surface and parallel to the longitudinal axis of the backmember. In addition, the thickness of the back member at the high levelof the step is greater than the thickness of the back member at one ofits ends.

[0006] Preferably, the shingle panel is composed of an asphalt materialand the upper surface of the shingle panel includes a granular materialthereon. Preferably, the composition of the shingle panel furtherincludes a rubberized material. The rubberized material is preferably astyrene-butadiene-styrene block copolymer. Preferably, the back memberis composed of an injection-molded thermoplastic. Alternatively, theback member may be composed of any rigid material suitable for outdoorexposure, such as molded recycled tire rubber, metal, or wood. If athermoplastic is used, the back member may include from about 40% to 70%filler by weight.

[0007] Preferably, the back member includes a trapezoid-shaped base anda plurality of walls extending from the base. The step in thickness ofthe back member is provided by a step in the height of the walls in across-sectional plane perpendicular to the base and parallel to thelongitudinal axis of the back member.

[0008] For installation with “ridge vent” systems (to be discussedbelow), the back member preferably includes channels formed thereincommunicating between a side of the back member and an area near thelongitudinal center axis of the shingle panel. Preferably, the channelsare formed in a zig-zag or herringbone pattern. Through the channels,the shingle according to the present invention is able to vent the airescaping through the ridge vent of the roof to the outside environment.

[0009] In yet another preferred embodiment of the invention, the backmember includes a planar base surface that is attached to thesubstantially planar lower surface of the shingle panel. Opposite theplanar base surface, the back member includes a surface inclined withrespect to the planar base surface and a surface parallel to the planarbase surface. At the juncture between the inclined surface and theparallel surface, there is formed the step in thickness of the backmember. In this embodiment, the back member preferably includes cavitiesformed therein. The cavities lighten the back member, but at the sametime do not substantially impair the rigidity of the back member.

[0010] According to another aspect of the present invention, the backmember is attached to the shingle panel using a novel asphalticadhesive. The asphaltic adhesive includes from about 62% to about 99% byweight of an asphalt cement; from about 0.5% to about 15% by weight of afirst thermoplastic having a glass-transition temperature in the rangefrom about 190° F. to about 260° F.; and from about 0.5% to about 15% byweight of a second thermoplastic having a glass-transition temperaturein the range from about −55° F. to about 0° F.

[0011] The grade of the asphalt cement may be any of the gradesspecified by the American Society for Testing and Materials in Tables 1to 3 of Publication D338 1-92, entitled “Standard Specification forViscosity-Graded Asphalt Cement for Use in Pavement Construction.” Ablend of different grades of asphalt cement may be used.

[0012] Preferably, the grade of the asphalt cement is AC-30 or below. Inaddition, it is preferred that the first thermoplastic is astyrene-butadiene-styrene block copolymer having a butadiene/styreneratio in the range of about 68/32 to about 84/16, a block polystyrene inthe range from about 30% to 32%, and an oil content in the range of fromabout 4.5 phr to 5.5 phr. It is also preferred that the secondthermoplastic is a styrene-isoprene-styrene (SIS) block polymer or alatex having a molecular weight in the range of about 100,000 to about100 million atomic units. The latex may be of a wide variety, includinganionic latex, cationic latex, and a combination thereof. Preferably,the latex comprises a styrene-butadiene rubber polymer having from about62% to about 70% polymer solids in water, a pH in the range of about5.25 to about 10.5, and a monomer ratio of butadiene to styrene in therange from about 74/26 to about 78/22.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Exemplary embodiments of the present invention will now bedescribed in detail with reference to the accompanying drawings inwhich:

[0014]FIG. 1 is an isometric view of a shingle according to a preferredembodiment of the present invention;

[0015]FIG. 2 is a bottom plan view of a shingle according to theembodiment of FIG. 1;

[0016]FIG. 3 is a side plan view of a shingle according to theembodiment of FIG. 1;

[0017]FIG. 4 is a top plan view of a back member of a shingle accordingto the embodiment of FIG. 1;

[0018]FIGS. 5 and 6 are side plan views of a shingle according to theembodiment of FIG. 1;

[0019]FIG. 7 is an isometric view of the placement of a series ofshingles after installation, each shingle constructed according to theembodiment of FIGS. 1 to 6;

[0020]FIG. 8 is a side plan view of a pair of shingles according toanother preferred embodiment of the present invention;

[0021]FIG. 9 is an isometric view of a back member of a shingleaccording to another preferred embodiment of the present invention;

[0022]FIG. 10 is a bottom plan view of a shingle including a back memberaccording to the embodiment of FIG. 9;

[0023]FIG. 11 is a side plan view of a shingle according to theembodiment of FIG. 10;

[0024]FIG. 12 is an isometric view of a back member according to theembodiment of FIG. 9;

[0025]FIG. 13 is a bottom plan view of a shingle according to anotherpreferred embodiment of the present invention;

[0026]FIG. 14 is a side plan view of a back member of a shingleaccording to the embodiment of FIG. 13; and

[0027]FIG. 15 is a side plan view of a shingle according to theembodiment of FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

[0028]FIG. 1 is an isometric view of a shingle 5 according to apreferred embodiment of the present invention. The shingle 5 includes ashingle panel 10 and a back member 20, which is attached to the bottomsurface 12 (see FIG. 2) of the shingle panel 10. The shingle panel 10may be in the form of any symmetrical shape, such as a rectangle or atrapezoid. As shown in FIGS. 1 and 2, however, the shingle panel 10 ispreferably trapezoid shaped because a trapezoid shape has been found toyield the best general appearance when the shingle 5 is installed.

[0029] The shingle panel 10 is composed of an asphalt material.Preferably, to enhance its flexibility and bending strength, the shinglepanel 10 is composed of a fiberglass-based SBS-modified asphaltmaterial, where SBS represents a styrene-butadiene-styrene blockcopolymer. As is well-known in the art, the upper surface 14 of theshingle panel 10 (the surface facing away from the roof when the shingleis installed) contains granular ceramic material embedded therein (notshown).

[0030] The back member 20 may be attached to the shingle panel 10 by anysuitable asphaltic adhesive. According to one aspect of the presentinvention, the back member 20 is preferably attached to the shinglepanel 10 by a novel asphaltic adhesive comprising from about 62% toabout 99% by weight of an asphalt cement; from about 0.5% to about 15%by weight of a first thermoplastic having a high glass-transitiontemperature (T_(g)); and from about 0.5% to about 15% by weight of asecond thermoplastic having a low glass-transition temperature (T_(g)).A preferred range for each of said first and second thermoplastics isfrom about 1% to about 7% by weight.

[0031] As used in this specification and the appended claims, a highglass-transition temperature refers to a glass-transition temperature inthe range from about 190° F. to about 260° F. and a low glass-transitiontemperature refers to a glass-transition temperature in the range fromabout −55° F. to about 0° F. The glass-transition temperature, as knownto those skilled in the art, refers to the temperature above which apolymer exhibits liquid-like properties. Advantageously, by combining athermoplastic with a high glass-transition temperature and athermoplastic with a low glass-transition temperature, the asphalticadhesive of the present invention provides excellent adhesiveperformance in both high temperatures and low temperatures. Thus, theasphaltic adhesive is suitable for a wide variety of geographiclocations, including those locations having wide seasonal temperaturevariations.

[0032] As used in this specification and the appended claims, asphaltcement refers to vacuum distillation bottoms. The grade of the asphaltcement that may be used in the present invention includes any of thegrades specified by the American Society for Testing and Materials(“ASTM”in Tables 1 to 3 of Publication D3381-92, entitled “StandardSpecification for Viscosity-Graded Asphalt Cement for Use in PavementConstruction” which is incorporated herein by reference. A blend ofdifferent grades of asphalt cement may also be used. Preferably, thegrade of the asphalt cement is AC-30 or below, as defined by the ASTM inPublication D3381-92. The requirements for asphalt cement of gradelevels AC-30 and below are given in Table 1. TABLE 1 Requirements forAsphalt Cement of Grades AC-30 and Below Viscosity Grades Test AC-2.5AC-5 AC-10 AC-20 AC-30 Viscosity, 140° F. (60° C.),P 250 ± 50 500 ± 1001000 ± 200 2000 ± 400 3000 ± 600 Viscosity, 275° F. (135° C.), min, cSt125 176 250 300 350 Penetration, 77° F. (25° C.), 100 g, 5s, min 220 14080 60 50 Flash point, Cleveland open cup, min, ° F. (° C.) 325 (163) 350(177) 425 (219) 450 (232) 450 (232) Solubility in trichloroethylene,min, % 99.0 99.0 99.0 99.0 99.0 Tests on residue from thin-film ovenheat: Viscosity, 140° F. (60° C.), max, P 1250 2500 5000 10000 150000Ductility, 77° F. (25° C.), 5 cm/min, min, cm 100^(a) 100 75 50 40

[0033] The thermoplastic having a low glass-transition temperature maybe a latex. The latex may be of a wide variety, including anionic latex,cationic latex, and a combination thereof, having a molecular weight inthe range from about 100,000 to about 100 million atomic units. Examplesof latex that may be used in the asphaltic adhesive of the presentinvention include butyl rubber latex, styrene-butadiene rubber latex,neoprene latex, polyvinyl alcohol emulsion latex, water-basedpolyurethane emulsion latex, water-based polyurethane elastomer latex,vinyl chloride copolymer latex, nitrile rubber latex, or polyvinylacetate copolymer latex.

[0034] Preferably, the latex is a high molecular weight, high mooneyviscosity styrene-butadiene rubber polymer latex that has the propertiesspecified in Table 2. TABLE 2 Latex Properties Property Range of ValuesTotal Solids, % by weight 62-70 pH 5.25-10.5 Viscosity (Brookfield), cps800-1650 Monomer Ratio (Butadiene/Styrene) 74/26-78/22 Pounds/GallonRatio 7.7-8.1

[0035] Alternatively, instead of latex, the thermoplastic with the lowglass-transition temperature may be a linear styrene-isoprene-styrene(SIS) block polymer, such as KRATON® D1107 thermoplastic, which ismanufactured and sold by Shell Chemicals Ltd.

[0036] Preferably, the thermoplastic with a high glass-transitiontemperature is a styrene-butadiene-styrene (SBS) block copolymer havingthe properties specified in Table 3. The methods referred to in the lastcolumn of Table 3 are methods published by the American Society forTesting and Materials. Examples of SBS thermoplastics that be may usedfor the thermoplastic with the high glass-transition temperature includethermoplastics sold under the brand names KRATON® D1101 (manufacturedand sold by Shell Chemicals Ltd.), FINA 409 (manufactured and sold byFina Oil and Chemical Co.), and FINA 411 (manufactured and sold by FinaOil and Chemical Co.). TABLE 3 Styrene-Butadiene-Styrene (SBS)Properties Property Range of Values Method Melt Flow at 180° C./5kg(g/10 min) 0.1-1.0 ASTMD-1238 Tensile Strength (psi) 2300-4600 ASTMD-638 Elongation at break (%) 550-820 ASTM D-638 300% modulus (psi)240-800 ASTM D-638 Shore A Hardness 71-82 ASTM D-2240 Butadiene/StyreneRatio 68/32-84/16 Block Polystyrene (%) 30-32 Oil Content (phr) 4.5-5.5Specific Gravity at 23° C. (g/cm³) 0.92-0.95 Refractive Index 1.44-1.64Viscosity of 5.2% Toluene 4-20 Solution (cSt) Color White Form Crumband/or Powder

[0037] Table 4 lists specific adhesive formulations in accordance withthe present invention. It is noted that the percentages used in Table 4are by weight of the asphaltic adhesive. These formulations are hot-meltadhesives, which are applied at temperatures of between 300 degrees and400 degrees F. TABLE 4 Specific Adhesive Formulations FormulationsCompound Manufacturer 1 2 3 4 5 6 7 8 GB AC-20 Golden Bear, 91.7% 90.9%94.3% 91.7% 92.2% 92.6% 91.7% Bakersfield, CA GB AC-5 Golden Bear, 91.2%Bakersfield, CA UP-70 Latex UltraPave, 1.4% 1.4% 1.3% 1.4% 0.9% 1.4% SBRDalton, GA, (Styrene- La Mirada, butadiene CA Rubber) UP-2897 UltraPave,1.0% Latex Dalton, GA, La Mirada, CA KRATON Shell 2.8% D1107 Chemicals(Styrene- Ltd. isoprene- styrene) Fina 409 SBS FINA Oil and 6.9% 7.7%4.7% 5.5% 6.4% 6.5% (Styrene- Chemical Co., butadiene- Carville, LAstyrene) Fina 411 SBS FINA Oil and 7.5% 6.9% (Styrene- Chemical Co.,butadiene- Carville, LA styrene)

[0038] Of the formulations listed in Table 4, formulations 1, 5, 7, and8 are preferred based on adhesive performance as determined by a SLUMPtest using 15-18 mil thick layers of the adhesive formulations. Ifcost-effectiveness of the formulations is taken into account, thepreferred formulation is formulation 7. If expense is not a factor,formulation 5 is preferred overall because of its performance, ease ofprocessing, ease of blending, and ease of storage.

[0039] Table 5 lists certain physical properties of the formulations ofTable 4, where experimental data for these formulations was available.The physical properties listed in Table 5 are merely exemplary and arenot intended to convey representative values. Indeed, as indicated bythe data for two different samples of formulation 1, the properties inTable 5 may vary widely due to the variability in the properties ofasphalt cement, even when the asphalt cement is of the same grade andobtained from the same manufacturer. The variation in these properties,however, does not greatly effect the adhesive performance of theformulations. TABLE 5 Physical Properities of Formulations (Final Blend)Formulations Physical 1 1 Properties (Sample 1) (Sample 2) 2 3 4 5 6 7 8Viscosities (centipoise) 350° F. 608 560 510 360° F. 1162 1667 1767 380°F. 845 1182 795 400° F. 399 630 907 540 373 315 450° F. 234 218 180Softening 215 221 231 214 197 208 210 Point (° F.) Penetration 38.2 35.031.0 41.0 40.1 (mm)

[0040] The mixing procedure for the formulations shown in Table 4includes, first, heating the asphalt cement in a mixing tank to atemperature of between 325° F. to 375° F. Second, the SBS rubber isadded to the asphalt cement, and the blend is mixed for about 45 to 120minutes, until all of the SBS rubber is swelled and no rubber particlesare observable. Next, the latex or the SIS thermoplastic material isadded to the blend at a temperature of 350° F. If latex is added,caution should be used in adding the latex because the temperature ofthe blend will cause the water in the latex to evaporate or bubble out.Moreover, latex should be added very slowly to the hot blend as addingthe latex too rapidly could splash the blend or could allow the blend toclimb up on the mixing stirrer. On complete addition of the latex, theblend is mixed for about 30 minutes. The blend is then ready to use.

[0041] The mixing procedure has been described with reference to amixing tank. Alternatively, instead of a tank, the mixing may also beperformed by injecting the materials through in-line piping, as iswell-known by those skilled in the art.

[0042] Cross-linking agents, from about 0.1% to about 2.5% by weight,may also be added to the formulations in Table 4. A preferred range forthe cross-linking agents is 0.1% to 0.2% by weight. The addition ofcross-linking agents allows less SBS to be used in each formulation;however, it also degrades the low-temperature performance of theasphaltic adhesive.

[0043] If cross-linking agents are to be added to the blend, thecross-linking agents are added after the latex or the SIS thermoplasticmaterial is mixed in. After adding the cross-linking agents, the blendis mixed for about four hours at a temperature of 350° F. to 380° F.Examples of suitable cross-linking agents that may be used in thepresent invention include the agents sold under the brand namesBUTAPHALT 720 (sold by Texpar Energy, Inc., Waukesha, Wis.), HVA-2 (soldby E.I. du Pont de Nemours and Company, Wilmington, Del.), and TETRONE(sold by E.I. du Pont de Nemours and Company, Wilmington, Del.).

[0044] If latex is used in the asphaltic adhesive, it is noted thatwater will evaporate out of the latex over time and the polymers in thelatex may cross-link with each other. Accordingly, if the asphalticadhesive includes latex, the asphaltic adhesive will become thicker andmore viscous over time.

[0045] The back member 20 is preferably manufactured from aninjection-molded thermoplastic material, such as injected-moldedpolystyrene, polypropylene, or polyethylene. The polystyrene,polypropylene, or polyethylene materials may be low, medium, or highdensity and may be used with 40% to 70% filler by weight. Such fillermay include limestone, gypsum, aluminum trihydrate (ATH), cellulosefiber, and plastic polymer fiber. Other thermoplastic materials that maybe used include ethylene-vinyl-acetate (EVA) polymer materials,ethylene-mythylene-acrylate (EMAC) materials, neoprene materials, andpolychlorosulfonated polymer (Hypalon) materials.

[0046] Although an injection-molded thermoplastic material is preferredfor the manufacture of the back member 20, any rigid material suitablefor outdoor exposure is also suitable. For example, molded recycled tirerubber, metal, or wood may also be used. If rubber is used, it ispreferred that amine be added to each of the adhesive formulations inTable 4. Up to 5% amine by weight may be added, but because amine's odoris unpleasant, the addition of 0.1% to 0.2% amine by weight ispreferred.

[0047]FIG. 2 is a bottom plan view of the shingle 5 of FIG. 1. As shownin FIG. 2, the base 25 of the back member 20 is also trapezoid-shaped,having substantially the same length as the shingle panel 10. Forexample, if the shingle panel 10 has a length of 13¼ inches, the backmember may be 13 inches long. The back member 20 is attached to theshingle panel 10 such that the longitudinal center axis 11 of theshingle panel 10 and the longitudinal center axis 21 of the base 25 arealigned. In addition, the short edge 13 of the shingle panel 10 and theshort edge 23 of the base 25 are also aligned. For the purposes of thisspecification, the end of the shingle 5 including the short edges of theshingle panel 10 and base 25 will be referred to as the trailing end,and the opposite end of the shingle 5 will be referred to as the frontend.

[0048] The back member 20 has two side walls 22 a and 22 b extendingfrom the base 25 along the base's longitudinal edges. The back member 20also has eight longitudinal walls 24 extending from the base 25, whichare parallel to the longitudinal axis 21 of the base 25, and eighttransverse walls 26 a-26h extending from the base 25, which areperpendicular to the longitudinal axis 21 of the base 25. Two of thetransverse walls 26 a and 26 e are disposed along the front edges of thebase 25.

[0049] The transverse walls 26 a-26 h are divided into two sets of fourwalls, which are disposed on opposite sides of the longitudinal centeraxis 21 of the base 25. The first set includes walls 26 a-26 d, and thesecond set includes walls 26 e-26h. In addition, wall 26 a is disposedopposite wall 26 e; wall 26 b is disposed opposite wall 26 f; wall 26 cis disposed opposite wall 26 gand wall 26 d is disposed opposite wall 26h. The opposing walls are offset from each other along the longitudinalcenter axis 21 by an amount ΔA sufficient to ensure that they do notinterfere with each other when the shingle 5 is folded—i.e., they areoffset from each other by an amount greater than the width of each wall.To facilitate the folding of the shingle 5, the back member 20preferably has a slit 27 in the base 25 along its longitudinal centeraxis 21. The base 25 also has rectangular holes 28 in the areas betweensome of the longitudinal walls 24 and the transverse walls 26 a-26 h.The holes 28 limit the twists and deformation of the base 25 under heat.

[0050]FIG. 3 is a side plan view of the shingle 5 of FIG. 1, viewedalong an axis perpendicular to the longitudinal center axis 11 of theshingle panel 10. As shown in FIG. 3, the side wall 22 a of the backmember 20 is composed of a wedge-shaped section 29 aand a rectangularsection 29 b. Transverse wall 26 b is positioned at the juncture betweensections 29 a and 29 b. At the juncture of the wedge-shaped section 29 aand rectangular section 29 b, there is a step in the height of the sidewall 22 a—i.e., the height of the wedge-shaped section 29 a is greaterthan the height of section 29 b.

[0051] Side wall 22 b is identical to sidewall 22 a. At any point alongthe longitudinal axis of the back member 20, the height of each of thelongitudinal walls 24 and the transverse walls 26 a-26 h corresponds tothe height of the sidewalls 22 a and 22 b at that longitudinal position.

[0052]FIG. 4 is a top plan view of the back member 20. The top surfaceof the base 25 is preferably corrugated, with the corrugations runninglongitudinally along the base 25. The corrugations facilitate theadherence of the back member 20 to the shingle panel 10. FIGS. 5 and 6are side plan views of the back member 20 viewed along axes parallel tothe longitudinal center axis 21 of the back member 20. FIGS. 5 and 6further illustrate the features of the back member 20 discussed above.

[0053]FIG. 7 is an isometric view of the placement of a series ofshingles 5 a, 5 b, and 5 c after installation on a hip, ridge, or rakeportion of a roof. Each of the shingles 5 a, 5 b, and 5 c is a shingleaccording to the embodiment of FIGS. 1 to 6, with the shingle panel 10folded along its longitudinal center axis 11 (see FIG. 2) to form aninverted V-shape with the back member 20 inside of the shingle panel 10.To begin the installation, shingle 5 a is placed on the hip, ridge, orrake portion of the roof and installed by nailing or other suitablemeans. Shingle 5 b is then placed on top of shingle 5 a, with the frontend of shingle 5 b placed on the trailing end of shingle 5 a. The frontend of shingle 5 b is then slid toward the front end of shingle 5 auntil the step of the back member 20 of shingle 5 b engages the edges atthe trailing end of shingle 5 a. Shingle 5 b is then nailed or otherwisesuitably fastened in place on the roof. Shingle 5 c is installed in thesame manner over shingle 5 b.

[0054] As will be appreciated by those skilled in the art, shinglesaccording to the present invention provide the following benefits.First, the step of the back member 20 allows the shingles to be easilyaligned with each other for a quick and uniform installation. Second,the thickness of the back member 20 enhances the appearance of theshingles and provides a wood-like look to the shingles. Third, since theback member 20 is substantially the same length as the shingle panel 10,the thickness of each shingle is enhanced across its entire length, andthe shingles thereby avoid an exaggerated “saw-tooth” appearance afterinstallation. Finally, since the back member 20 of each shingle is madeof a rigid material, the shingles will not droop over time or under heatand lose their thick, wood-like appearance.

[0055]FIG. 8 is a side plan view of a pair of shingles 100 a and 100 baccording to another preferred embodiment of the present invention. Eachof the shingles 100 a and 100 b includes a shingle panel 110 and a backmember 120 similar to the shingle panel 10 and back member 20,respectively, of FIGS. 1 to 6. A difference between the back member 120of FIG. 8 and the back member 20 of FIGS. 1 to 6 is that the step of theback member 120 is angled so that when the shingles 100 a and 100 b areinstalled, the shingles 100 a and 100 b interlock with one another.

[0056] FIGS. 9 to 12 illustrate a shingle 200 according to anotherpreferred embodiment of the present invention, which incorporates aventilation function for “ridge vent” systems. Presently, many homes areconstructed such that the peak of a roof has an opening of approximatelytwo inches along its length. This opening is covered by a special “ridgevent” material that allows air to pass out of the home, but preventsinsects and moisture from entering into the home. The “ridge vent”material is then covered by standard ridge shingle products. Clearly, atwo-step process is currently necessary for the installation of shingleson homes using a “ridge vent” system.

[0057]FIG. 9 is an isometric view of a back member 220 according to apreferred embodiment of the present invention, and FIG. 10 is a bottomplan view of the back member 220. As in the previous embodiments, theback member 220 includes a trapezoid-shaped base 225. The base 225includes a slit 227 along its longitudinal center axis 221 to facilitatethe folding of the back member 220.

[0058] Six transverse walls 226 a-226 f extend from the base 225 and runin a direction perpendicular to the longitudinal center axis 221 of thebase 225. The transverse walls 226 a-226 f are divided into two sets ofthree walls, which are disposed on opposite sides of the longitudinalcenter axis 221. The first set includes walls 226 a-226 c, and thesecond set includes walls 226 d-226 f. In addition, wall 226 a isdisposed opposite wall 226 d; wall 226 b is disposed opposite wall 226e; and wall 226 c is disposed opposite wall 226 f. The opposing wallsare offset from each other along the longitudinal center axis 221 by anamount ΔA sufficient to ensure that they do not interfere with eachother when the shingle 200 is folded—i.e., they are offset from eachother by an amount greater than the width of each wall.

[0059] Between the trailing edge of the base 225 and the transversewalls 226 c and 226 f, four walls 224 parallel to the longitudinalcenter axis 221 of the back member 220 extend from the base 225. Inaddition, in this area, there are disposed two side walls 222 extendingfrom the longitudinal edges of the base 225.

[0060] Between the transverse walls 226 a and 226 c and the transversewalls 226 d and 226 f, there are disposed a plurality of channel walls230 extending from the base 225. The channel walls 230 are preferablyarranged in a zig-zag or herringbone pattern and form channelscommunicating between the sides of the back member 220 and the centralportion of the back member 220 (the area around the longitudinal centeraxis 221 of the back member 220). In addition, along the longitudinaledges of the base 225, there are disposed pins 232 extending from thebase 225. Preferably, the pins 232 are spaced apart so that the width ofeach of the openings along the sides of the back member 225 is less than¼ inch.

[0061] When a shingle 200 with back member 220 is placed on a ridge ventroof, the air being vented from the ridge of the roof passes through thechannels formed by the channel walls 230 and into the outsideenvironment. Advantageously, the zig-zag or herringbone pattern of thechannel walls 230 prevents the entry of water into the ridge vent byforcing the water to take a tortuous path through the back member 220.In addition, the pins 232 prevent the penetration of insects into theback member 220 by restricting the width of the openings in the sides ofthe back member 220. Accordingly, the installation of ridge ventmaterial underneath the shingle 200 is not necessary, and only aone-step installation process is necessary to install shingles accordingto this embodiment on a ridge vent roof.

[0062]FIG. 11 is a side plan view of the back member 220, showing theback member 220 includes the same step feature as the back member 20 ofFIGS. 1 to 6. Dividing the back member 220 into two sections 229 a and229 b for the purposes of discussion (with the transverse wall 226 eserving as the partition between the two sections), the walls in section229 a increase in height along the longitudinal axis of the back member220 from the trailing edge of the base 225 to the transverse wall 226 e.In section 229 b, all of the walls have the same height, which is lessthan that of the transverse wall 226 e. The difference in height betweenthe walls in section 229 a and the walls in section 229 b provides thestep in thickness of the back member 220.

[0063]FIG. 12 is an isometric view of the back member 220. The topsurface of the base 225 is preferably corrugated, with the corrugationsrunning longitudinally along the base 225. The corrugations facilitatethe adherence of the back member 220 to the shingle panel 210.

[0064] As shown in FIGS. 9, 10, and 12, between the trailing edge of thebase 225 and the transverse walls 226 c and 226 f, there are disposed aplurality of circular holes 228 in the base 225. If the shingle panel210 is made shorter than the base 225 (not shown), the holes 228 providea further of means of ventilation for the air escaping the ridge vent ofthe roof.

[0065]FIG. 13 is a bottom plan view of a shingle 300 according toanother preferred embodiment of the present invention. The shingle 300includes a shingle panel 310 having attached thereto two back members320 a and 320 b. The back members 320 a and 320 b are mirror images ofeach other and are placed on the shingle panel 310 in symmetricalrelation with respect to the longitudinal center axis 311 of the shinglepanel 310.

[0066]FIG. 14 is a side plan view of back member 320 a, viewed from anaxis perpendicular to the longitudinal center axis 311 of the shinglepanel 310. (The corresponding side plan view of back member 320 b is thesame.) The back member 320 aincludes a planar base surface 325 a, whichis attached to the shingle panel 310. Opposite the planar base surface325 a, the back member has a planar surface 324 a that is inclined withrespect to the base surface 325 a and a planar surface 326 a that isparallel to the base surface 325 a. At the juncture between the surfaces324 a and 326 a, the height of surface 324 a is greater than the heightof surface 326 a, thereby producing a step in the thickness of the backmember 320 a. The back members 320 a and 320 b preferably include aplurality of rectangular-shaped cavities 328 a and 328 b therein,respectively, which lighten the back members and reduce the materialneeded to construct them.

[0067]FIG. 15 is a side plan view of shingle 300, viewed from the frontend along an axis parallel to the longitudinal center axis 311 of theshingle panel 310. The back member 320 a has side walls 321 a and 322 a,and the back member 320 b has side walls 321 b and 322 b. The side wallsof each back member 320 a and 320 b are angled inwardly with respect toeach back member 320 a and 320 b. The angling of side walls 322 a and322 b is necessary to ensure that these side walls do not interfere witheach other when the shingle panel 310 is folded.

[0068] Although the present invention has been described with referenceto certain preferred embodiments, various modifications, alterations,and substitutions will be apparent to those skilled in the art withoutdeparting from the spirit and scope of the invention, as defined by theappended claims.

We claim:
 1. A hip, ridge, or rake shingle comprising: a shingle panelhaving a substantially planar lower surface and an upper surface; and atleast one rigid back member having a length substantially the same as orgreater than the length of said shingle panel and attached to saidsubstantially planar lower surface of said shingle panel, said at leastone rigid back member having a step in thickness in a cross-sectionalplane perpendicular to said substantially planar lower surface andparallel to the longitudinal axis of said at least one rigid backmember, the thickness of said at least one rigid back member at the highlevel of said step being greater than the thickness of said at least onerigid back member at an end of said at least one rigid back member. 2.The hip, ridge, or rake shingle of claim 1, wherein said shingle panelis composed of an asphalt material and said upper surface of saidshingle panel includes a granular material thereon.
 3. The hip, ridge,or rake shingle of claim 2, wherein said shingle panel further comprisesa rubberized material.
 4. The hip, ridge, or rake shingle of claim 3,wherein said rubberized material is a styrene-butadiene-styrene blockcopolymer.
 5. The hip, ridge, or rake shingle of claim 1, wherein saidat least one rigid back member includes a trapezoid-shaped base and aplurality of walls extending from said base, said walls having a step inheight in a cross-sectional plane perpendicular to said base andparallel to the longitudinal axis of said at least one rigid backmember, said step in height of said walls providing said step inthickness of said at least one rigid back member.
 6. The hip, ridge, orrake shingle of claim 5, wherein said plurality of walls includes firstand second sets of walls disposed on opposite sides of and perpendicularto the longitudinal center axis of said at least one rigid back member.7. The hip, ridge, or rake shingle of claim 6, wherein each wall in saidfirst set of walls and a corresponding wall in said second set of wallsare offset from each other along the longitudinal center axis of said atleast one rigid back member by an amount greater than the width of eachwall.
 8. The hip, ridge, or rake shingle of claim 5, wherein said baseincludes corrugations on the surface to be attached to saidsubstantially planar lower surface of said shingle panel.
 9. The hip,ridge, or rake shingle of claim 5, wherein said base includes a slitalong its longitudinal center axis for facilitation of folding of saidat least one rigid back member.
 10. The hip, ridge, or rake shingle ofclaim 1, wherein said step is capable of interlocking with an end of ashingle which is substantially identical to said hip, ridge, or rakeshingle.
 11. The hip, ridge, or rake shingle of claim 1, wherein said atleast one rigid back member includes channels formed thereincommunicating between a side of said at least one rigid back member andan area near the longitudinal center axis of said shingle panel, wherebywhen said shingle is installed on a ridge vent roof, said channels allowventilation of the roof to the outside environment.
 12. The hip, ridge,or rake shingle of claim 11, wherein said channels are arranged in azig-zag or herringbone pattern.
 13. The hip, ridge, or rake shingle ofclaim 11, wherein the width of the openings of said channels along thesides of said at least one rigid back member is less than or equal to ¼inch.
 14. The hip, ridge, or rake shingle of claim 11, wherein said atleast one rigid back member includes a trapezoid-shaped base and aplurality of walls extending from said base, said plurality of wallsforming said channels.
 15. The hip, ridge, or rake shingle of claim 14,wherein said at least one rigid back member includes a plurality of pinsextending from the longitudinal edges of said base.
 16. The hip, ridge,or rake shingle of claim 1, wherein said at least one rigid back memberincludes a planar base surface that is attached to said substantiallyplanar lower surface of said shingle panel, a surface inclined withrespect to said planar base surface, and a surface parallel to saidplanar base surface; and wherein said step in thickness of said at leastone rigid back member is formed at the juncture of said inclined surfaceand said parallel surface.
 17. The hip, ridge, or rake shingle of claim16, wherein said at least one rigid back member includes cavities formedtherein.
 18. The hip, ridge, or rake shingle of claim 1, wherein said atleast one rigid back member is composed of an injection-moldedthermoplastic material.
 19. The hip, ridge, or rake shingle of claim 18,wherein said thermoplastic material is selected from the groupconsisting essentially of polystyrene, polypropylene, polyethylene,ethylene-vinyl-acetate (EVA), ethylene-mythylene-acrylate (EMAC),neoprene, and polychlorosulfonated polymer (Hypalon).
 20. The hip,ridge, or rake shingle of claim 19, wherein said at least one rigid backmember further includes from about 40% to about 70% filler by weight.21. The hip, ridge, or rake shingle of claim 20, wherein said filler isselected from the group consisting essentially of limestone, gypsum,aluminum trihydrate, cellulose fiber, and plastic polymers fiber. 22.The hip, ridge, or rake shingle of claim 1, wherein said at least onerigid back member is composed of a material selected from the groupconsisting essentially of molded recycled tire rubber, metal, and wood.23. An asphaltic adhesive for use with roofing material, comprising:from about 62% to about 99% by weight of an asphalt cement; from about0.5% to about 15% by weight of a first thermoplastic having aglass-transition temperature in the range from about 190° F. to about260° F.; and from about 0.5% to about 15% by weight of a secondthermoplastic having a glass-transition temperature in the range fromabout −55° F. to about 0° F.
 24. The asphaltic adhesive of claim 23,comprising from about 1% to about 7% by weight of said firstthermoplastic and from about 1% to about 7% by weight of said secondthermoplastic.
 25. The asphaltic adhesive of claim 23, wherein saidfirst thermoplastic is a styrene-butadiene-styrene block copolymer. 26.The asphaltic adhesive of claim 25, wherein saidstyrene-butadiene-styrene block copolymer has a butadiene/styrene ratioin the range of about 68/32 to about 84/16, a block polystyrene in therange from about 30% to 32%, and an oil content in the range of fromabout 4.5 phr to 5.5 phr.
 27. The asphaltic adhesive of claim 23,wherein said second thermoplastic is a styrene-isoprene-styrene blockpolymer.
 28. The asphaltic adhesive of claim 23, wherein said secondthermoplastic is a latex having a molecular weight in the range of about100,000 to about 100 million atomic units.
 29. The asphaltic adhesive ofclaim 28, wherein said latex comprises a styrene-butadiene rubberpolymer.
 30. The asphaltic adhesive of claim 29, wherein saidstyrene-butadiene rubber polymer comprises from about 62% to about 70%polymer solids in water, has a pH in the range of about 5.25 to about10.5, and has a monomer ratio of butadiene to styrene in the range fromabout 74/26 to about 78/22.
 31. The asphaltic adhesive of claim 23,wherein the grade of said asphalt cement is AC-30 or below.
 32. Theasphaltic adhesive of claim 23, further comprising from about 0.1% toabout 2.5% by weight of one or more cross-linking agents.
 33. Theasphaltic adhesive of claim 23, further comprising from about 0.1% to5.0% by weight of amine.
 34. A method of producing an asphalticadhesive, comprising the steps of: heating an asphalt cement to atemperature of between 325° F. to 375° F.; mixing into said asphaltcement a first thermoplastic having a glass-transition temperature inthe range from about 190° F. to about 260° F.; and mixing into the blendof said asphalt cement and said first thermoplastic a secondthermoplastic having a glass-transition temperature in the range fromabout −55° F. to about 0° F.; wherein said blend of asphalt cement,first thermoplastic, and second thermoplastic comprises from about 62%to about 99% by weight of said asphalt cement; from about 0.5% to about15% by weight of said first thermoplastic; and from about 0.5% to about15% by weight of said second thermoplastic.